This disclosure relates generally to a radio frequency transceiver, and more, specifically to an envelope tracking system in a radio frequency transceiver.
Envelope Tracking (ET) systems are commonly utilized in the radio frequency (RF) transmitter section of a radio where power efficiency is important such as in cellular radios used in mobile phones. A typical ET system includes an RF power amplifier (PA) utilizing a variable power supply, which supplies the PA with a dynamically changing supply voltage that tracks the amplitude of the modulation. The goal of such an ET system is generally to improve efficiency by operating the PA with low headroom.